A scientific explanation for ghosts? - Infrasound is an extremely low frequency between between .1 -20Hz. It is so low, that humans cannot hear it. But we can feel it. A good portion of the population is also thought to be hypersensitive to these low frequencies. Infrasound can cause bizarre effects, including nausea, extreme fear or awe, anxiety and chills. Researchers also believe it affects vision by causing vibrations of the eyeball. These vibrations can cause you to â€˜seeâ€™ ghostsFrom cw